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GemmologyThe Journal of Volume 35 / No. 1 / 2016 The Gemmological Association of Great Britain Save the date Gem-A Conference Saturday 5 and Sunday 6 November 2016 Visit www.gem-a.com for the latest information Join us. The Gemmological Association of Great Britain, 21 Ely Place, London, EC1N 6TD, UK. T: +44 (0)20 7404 3334 F: +44 (0)20 7404 8843. Registered charity no. 1109555. A company limited by guarantee and registered in England No. 1945780. Registered Office: 3rd Floor, 1-4 Argyll Street, London W1F 7LD. Conference_03-2016_March-April_Save The Date_A4.indd 1 12/04/2016 10:44:17 Contents GemmologyThe Journal of Volume 35 / No. 1 / 2016 COLUMNS p. 22 1 What’s New DiamondDect for diamond identification|Triple D photo kit|Upgraded Diamond- View|Variofoc LED lighting system|AGTA Tucson seminars| Responsible sourcing of coloured stones report|World Gold Council report|GSJ 2015 Annual Meeting abstracts|ICGL Newsletter|Large CVD synthetic diamond seen p. 64 by HRD Antwerp|MAGI diamond type report|SSEF Facette|Updated Journal cumulative index|Wyoming jade report|GemeSquare app and GemePrice 5.0|Historical reading lists|Hyperion inclusion search engine|Gems from the French Crown Jewels exhibit ARTICLES 6 Gem Notes Apatite from Iran|Purple apa- Feature Articles tite from Namibia|Cordierite from Madagascar|Emerald 28 Characterization of Oriented Inclusions in Cat’s-eye, and pyrite mixture from Co- Star and Other Chrysoberyls lombia|Garnet from Mahenge, By Karl Schmetzer, Heinz-Jürgen Bernhardt and H. Albert Gilg Tanzania|Grandidierite from Madagascar|Lalique quartz pen- dant in polarized light|Faceted 56 The Great Mughal and the Orlov: One and the Same quartz with petroleum inclu- Diamond? sions from Pakistan|Quartz slabs By Anna Malecka from Inner Mongolia|Sphalerite inclusions in quartz|Ruby from Gemmological Brief Liberia|Unstable yellow colour in sapphire|Petroleum inclusion 64 A Lead-Glass-Filled Corundum Doublet in pink spinel|Spurrite from New By Supparat Promwongnan, Thanong Leelawatanasuk and Mexico, USA|Tsavorite mining at Saengthip Saengbuangamlam the Scorpion mine, Kenya|Mussel pearls from the Philippines 70 Conferences Accredited Gemologists Association|Gemstone Industry & Laboratory Cover Photo: Cat’s-eye chrysoberyls are Conference|Jewelry Industry Summit shown here in a gold ring (11.71 ct oval), as loose round cabochons (11.00 75 Gem-A Notices and 14.09 ct) and mounted in gold cufflinks (6.48–8.89 ct). Courtesy of The 78 Learning Opportunities Edward Arthur Metzger Gem Collection at the Heasley Museum, Cornell 82 New Media University, Ithaca, New York, USA; composite photo by Jeff Scovil. 86 Literature of Interest The Journal is published by Gem-A in collaboration with SSEF and with the support of AGL and GIT. ISSN: 1355-4565, http://dx.doi.org/10.15506/JoG.2016.35.1 i The Journal of emmology G THE GEMMOLOGICAL ASSOCIATION OF GREAT BRITAIN Editor-in-Chief Production Editor Marketing Consultant Brendan M. Laurs Mary A. Burland Ya’akov Almor [email protected] [email protected] [email protected] 21 Ely Place Editorial Assistant Editor Emeritus Assistant Editor London EC1N 6TD Carol M. Stockton Roger R. Harding Michael J. O’Donoghue UK Associate Editors t: +44 (0)20 7404 3334 Edward Boehm, RareSource, Chattanooga, Tennessee, USA; Alan T. Collins, King’s College f: +44 (0)20 7404 8843 London; John L. Emmett, Crystal Chemistry, Brush Prairie, Washington, USA; Emmanuel e: [email protected] Fritsch, University of Nantes, France; Rui Galopim de Carvalho, Portugal Gemas, Lisbon, w: www.gem-a.com Portugal; Lee A. Groat, University of British Columbia, Vancouver, Canada; Thomas Hainschwang, GGTL Laboratories, Balzers, Liechtenstein; Henry A. Hänni, GemExpert, Registered Charity No. 1109555 Basel, Switzerland; Jeff W. Harris, University of Glasgow; Alan D. Hart, The Natural History Registered office: Palladium House, Museum, London; Ulrich Henn, German Gemmological Association, Idar-Oberstein; Jaroslav 1–4 Argyll Street, London W1F 7LD Hyršl, Prague, Czech Republic; Brian Jackson, National Museums Scotland, Edinburgh; Stefanos Karampelas, GRS Gemresearch Swisslab, Lucerne, Switzerland; Lore Kiefert, Gübelin Gem Lab Ltd., Lucerne, Switzerland; Hiroshi Kitawaki, Central Gem Laboratory, Tokyo, Japan; Michael S. Krzemnicki, Swiss Gemmological Institute SSEF, Basel; Shane F. McClure, Gemological Institute of America, Carlsbad, California; Jack M. Ogden, Striptwist President Ltd., London; Federico Pezzotta, Natural History Museum of Milan, Italy; Jeffrey E. Post, Harry Levy Smithsonian Institution, Washington DC, USA; Andrew H. Rankin, Kingston University, Surrey; George R. Rossman, California Institute of Technology, Pasadena, USA; Karl Vice Presidents Schmetzer, Petershausen, Germany; Dietmar Schwarz, AIGS Lab Co. Ltd., Bangkok, Thailand; David J. Callaghan, Alan T. Collins, Menahem Sevdermish, GemeWizard Ltd., Ramat Gan, Israel; Guanghai Shi, China University Noel W. Deeks, E. Alan Jobbins, of Geosciences, Beijing; James E. Shigley, Gemological Institute of America, Carlsbad, Michael J. O’Donoghue, California; Christopher P. Smith, American Gemological Laboratories Inc., New York, New Andrew H. Rankin York; Evelyne Stern, London; Elisabeth Strack, Gemmologisches Institut Hamburg, Germany; Tay Thye Sun, Far East Gemological Laboratory, Singapore; Pornsawat Wathanakul, Gem Honorary Fellows and Jewelry Institute of Thailand, Bangkok; Chris M. Welbourn, Reading, Berkshire; Joanna Gaetano Cavalieri, Terrence Whalley, Victoria and Albert Museum, London; Bert Willems, Leica Microsystems, Wetzlar, S. Coldham, Emmanuel Fritsch Germany; Bear Williams, Stone Group Laboratories LLC, Jefferson City, Missouri, USA; J.C. (Hanco) Zwaan, National Museum of Natural History ‘Naturalis’, Leiden, The Netherlands. Honorary Diamond Member Martin Rapaport Content Submission The Editor-in-Chief is glad to consider original articles, news items, conference/excursion Honorary Life Members reports, announcements and calendar entries on subjects of gemmological interest for Anthony J. Allnutt, Hermann Bank, publication in The Journal of Gemmology. A guide to the various sections and the preparation Mary A. Burland, Terence M.J. Davidson, of manuscripts is given at www.gem-a.com/publications/journal-of-gemmology/submit- Peter R. Dwyer-Hickey, Gwyn M. Green, an-article.aspx, or contact the Production Editor. Roger R. Harding, John S. Harris, Subscriptions J. Alan W. Hodgkinson, John I. Koivula, Gem-A members receive The Journal as part of their membership package, full details of Jack M. Ogden, C.M. (Mimi) Ou Yang, which are given at www.gem-a.com/membership.aspx. Laboratories, libraries, museums and Evelyne Stern, Ian Thomson, Vivian P. similar institutions may become Direct Subscribers to The Journal (see www.gem-a.com/ Watson, Colin H. Winter publications/subscribe.aspx). Interim Chief Executive Officer Advertising Nicholas H. Jones Enquiries about advertising in The Journal should be directed to the Marketing Consultant. For more information, see www.gem-a.com/publications/journal-of-gemmology/advertising- Council in-the-journal.aspx. Miranda E.J. Wells – Chair Kathryn L. Bonanno, Mary A. Burland, Database Coverage Justine L. Carmody, Paul F. Greer, Kerry The Journal of Gemmology is covered by the following abstracting and indexing services: H. Gregory, J. Alan W. Hodgkinson, Australian Research Council academic journal list, British Library Document Nigel B. Israel, Jack M. Ogden, Richard Supply Service, Chemical Abstracts (CA Plus), Copyright Clearance Center’s M. Slater, Christopher P. Smith RightFind application, CrossRef, EBSCO (Academic Search International, Discovery Service and TOC Premier), Gale/Cengage Learning Academic Branch Chairmen OneFile, GeoRef, Mineralogical Abstracts, ProQuest, Scopus and the Thomson Midlands – Georgina E. Kettle Reuters’ Emerging Sources Citation Index (in the Web of Science). North East – Mark W. Houghton South East – Veronica Wetten Copyright and Reprint Permission South West – Richard M. Slater Full details of copyright and reprint permission are given on The Journal’s website. The Journal of Gemmology is published quarterly by Gem-A, The Gemmological Association of Great Britain. Any opinions expressed in The Journal are understood to be the views of the contributors and not necessarily of the publisher. Printed by DG3 (Europe) Ltd. ™ © 2016 The Gemmological Association of Great Britain Understanding Gems ISSN: 1355-4565 Cert no. TT-COC-002454 ii The Journal of Gemmology, 35(1), 2016 What’s New INSTRUMENTS AND TECHNIQUES DiamondDect Diamond Identification Instrument Upgraded DiamondView Instrument TaiDiam Technology Co. Ltd. (Zhengzhou, China) an- In June 2015, the De Beers Group of Companies nounced in September 2015 the availability of the released through its International Institute of DiamondDect portable diamond identification instru- Diamond Grading & Research an enhanced version ment from its associated company Krisdiam. Weigh- of the DiamondView. The upgraded instrument ing approximately 8 kg, the instrument includes a produces a surface fluorescence image that polariscope, microscope, fibre-optic illuminator and provides information on a sample’s growth history more, plus a Windows- that is useful for separating natural from synthetic based computer tablet diamonds. The upgraded model has changeable equipped with iden- filters that are useful tification software to for enhancing features separate CVD and shown by some synthetic HPHT synthetics from diamonds, particularly natural diamonds.
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  • SOME UNUSUAL SILLIMANITE CAT's-EYES by E

    SOME UNUSUAL SILLIMANITE CAT's-EYES by E

    NOTES AND NEW TECHNIQUES SOME UNUSUAL SILLIMANITE CAT'S-EYES By E. Giibelin, M, Weibel, and C. P. Woensdregt Brown-black sillimanite cat's-eyes from Sri Lanka thin-section study and the ion etching necessary present an unusually sharp band, which would make for subsequent electron diffraction. them extraordinary gems wereit not for therather un- This article summarizes the results of the elec- attractive body color of the stones. A study of six of tron microscope study of the inclusions causing these stones found that they contain 0.5 wt.% iron the chatoyancy, as well as the gemological charac- oxide. The principal inclusion mineral is ilmenite, teristics of this unusual material. which occurs in elongated, submicroscopically thin lamellae. Complex thicker lamellae consist of hercy- EXPERIMENTAL METHODS nite spinel grown together with a member of the pyroxene group. These thicker inclusions were not Chatoyancy, like asterism, is caused by the scat- foundin all of the specimens investigated. tering of light on numerous fibrous inclusions aligned in one or more directions in the host crys- tal; proper cutting en cabochon is required to re- veal the phenomenon. For good chatoyancy or asterism, the elongated inclusions must be thin sillimanite, also known as fibrolite, is a common compared to the wavelengths of light (Weibel, metamorphic mineral. Cuttable material is ex- 1985). Such minute crystal individuals are not ac- tremely rare but is found in the Mogok Stone Tract cessible to ordinary microscopy and X-ray analy- of Burma and in the Sri Lankan gem gravels, as sis. Even though the inclusions may show up in a transparent rounded crystals with a blue, violet- thin section viewed with a polarizing microscope, blue, or grayish green hue (Webster, 1983).